1. Field of the Invention
The invention relates to machines for embossing cards with alphanumerical text of the type used for credit cards, promotional cards and the like.
2. Description of the Prior Art
High speed card embossing systems are in wide spread use today which emboss hundreds of millions of cards per year. While prior art card embossing machines are capable of performing embossing at high speed with high reliability, these machines nevertheless suffer from several disadvantages. Many prior art commercially available embossers are high in price, sizeable, have a relatively high energy consumption because of the mass of the driven components and are complex because of requirements to emboss cards with different formats with multiple pitch characters.
U.S. Pat. No. 4,180,338, which is typical of prior art card embossers, discloses an embossing system which uses a single embossing wheel to emboss alpha numerical text on a plurality of vertically separated horizontally extending lines on a single card. The vertically separated horizontally extending lines are embossed by the translation of a single carriage holding a card to be embossed in orthogonal directions to position on the card with respect to the embossing wheel at those positions which characters are to be embossed. To emboss each character, the card is translated to the correct embossing position between the punch and die wheels prior to the activation of an activating mechanism for the chosen punch and die. Many commercially available embossing machines use a single orthogonally movable carriage in cooperation with a single embossing wheel having characters of both a 7-pitch size (7 characters per inch) and a 10-pitch size (10 characters per inch) to emboss cards. The translation of the carriage in orthogonal directions and the activation of the single punch and die pairs of the embossing wheels require sophisticated electrical-mechanical control.
U.S. Pat. No. 4,378,733 discloses an embosser for credit cards which is powered by a horizontally disposed drive shaft and the height of the embossed characters is controlled by adjustment of the location of interposers located between pairs of punch and die character elements and reciprocated arms which power the embossing operation.
U.S. Pat. No. 4,519,600 discloses a credit card embossing system having a transport which picks up a single card from an input hopper, moves the card past an embossing station and releases the card after embossing of the card is complete. The transport has a pair of cam actuated jaws which grip the card during transport through the embossing station.
U.S. Pat. No. 3,820,455 discloses an embossing system having separate embossing units for respectively embossing OCR characters and two or more lines of A/N (alphanumerical) characters. The separate embossing units each have a separate transport track which conveys the cards past the embosser. A feeder mechanism transfers the cards between successive tracks. The transport track for conveying cards to be embossed with OCR characters is advanced at a different rate of speed than the transport track which conveys cards to be embossed with A/N characters.
U.S. Pat. Nos. 3,638,563, 3,861,299 and Re 27,809 disclose a credit card embossing system having separate embossing units for embossing each line of characters on a credit card with lines of characters having at least two pitches. Different transport tracks drive the cards through the separate embossing units. The transport track for conveying cards to be embossed with OCR characters is advanced at a different rate of speed than the transport track which conveys cards to be embossed with A/N characters.
The Model 15000 embossing machine which is manufactured by Data Card Corporation uses a plurality of separate embossing units which each emboss a separate one of the vertically separated horizontally extending lines found on a conventional credit card or promotional card. The individual embossing units are dedicated to embossing characters of a single pitch which may be either 7 or 10 pitch size. A separate card transporting belt is provided with each embosser to move the card past the embosser with the card being transferred between the separate belts in order to emboss all of the lines of characters on the card which deleteriously affects throughput. The individual embossing units have a mechanism which continuously activates selected punch and dies positioned at the circumferential position of the embossing wheel where embossing takes place without interposers of the type used in the embossing wheel of U.S. Pat. No. 4,180,338. When a position on the horizontal line being embossed does not have a character to be embossed, the embossing wheel is rotated to a circumferential position which does not have a punch and die pair so that the mechanism which continuously activates the pairs of punch and die wheels does not have to be stopped. This embosser does not synchronously drive the individual embossing wheels from a common power source. The axis of the power drive for the embossers is horizontally disposed which prevents the individual embossers from being closely spaced horizontally in line with respect to each other which deleteriously affects the throughput of the system because of the time required to transport cards between successive embossing stations.
Commercial embossers for credit cards use a topper to apply a colored plastic coating to the top of the embossed characters for highlighting. These toppers heat fuse a layer of colored plastic borne on a foil to the embossed characters by the activation of a ram which drives a heated platen against the back surface of the foil to drive the front surface bearing the plastic coating into contact with the embossed characters. While these toppers produce a commercially acceptable topping, they have deficiencies. In the first place, the heated platen can cause the grease in the lubrication points of a ram which drives the platen to degrade because of the proximity of the platen to the ram which can necessitate shutdown for service. Moreover, the dissipation of heat from the platen to other mechanical parts can cause failure of these parts. The changing of the roll of plastic bearing foil is difficult because there is no access which permits a roll of foil to be threaded on the foil driving mechanism without feeding the leading edge of the foil sequentially over the foil guides along the path that the foil normally travels. Typically the foil is spliced onto the existing roll to avoid the threading process which is a time consuming and somewhat involved task.